| Riveting is one of the most important connection type in aircraft assembly,and the riveting zone is vulnerable to fatigue damage.How to improve the quality of riveting and prolong the life of aircraft structure has become the research focus of new riveting technology.Meanwhile,it is particularly important to improve the automation and intelligence level of assembly.The present research is aimed at the riveting technology of a dual-robot electromagnetic riveting system,and this thesis focuses on the research of its technological parameters,solves the technical difficulties of electromagnetic riveting of robots,and searches for reasonable technological parameters of electromagnetic riveting to improves the structural strength and fatigue life of riveted parts.The main research contents are as follows:(1)The influence of stress wave transmission in U-shaped jacking shim on the protruding amount of the riveting head was studied.The importance of setting delay trigger time of electromagnetic riveter was emphasized,and the theoretical delay time was derived.The appropriate delay trigger time of the riveter was determined by experiments,which could ensure that the protrusion size of riveted head is within 0.1mm.(2)The buffering effect of the cylinder on the recoil of electromagnetic riveting was studied.And the robot riveting system impacted by recoil force was studied via finite element simulation and validated by experimental tests.The results show that the recoil has litter effect on the end-effector and the robot,and the vibration amplitude of the end-effector is within the allowable range.(3)The electromagnetic riveting process was simulated by finite element method,and the inclination angle of the rivet die,initial fit clearance and the rivet length was set as variables.The variation law of interference-fit percentage,stress-strain and shear band distribution under different parameters were analyzed,and the electromagnetic riveting force variation curve is extracted.The electromagnetic riveting process parameters of 2A10 aluminum alloy rivet with a diameter of 5mm are summarized.(4)Based on the dual-robot electromagnetic riveting test platform,the riveting test with various angle of the rivet die,initial fit clearance and the rivet length was conducted.and the variation law of riveting interference-fit size was obtained.The strength test of electromagnetic riveting and pressure riveting specimens is carried out,reasonable process parameters can improve the strength of the electromagnetic riveting structure,which is much higher than that of press riveting. |
PDF Full Text Request